Cara Kerja Dioda PN Junction | Kuliah Fisika Semikonduktor

Introduction

This tutorial explains how a PN junction diode works, which is fundamental in semiconductor physics. Understanding diodes is crucial for anyone interested in electronics, as they are essential components in various devices, including rectifiers, signal modulators, and more.

Step 1: Understand the Structure of a PN Junction

• PN Junction Basics: A PN junction is formed by combining p-type and n-type semiconductors.
• P-Type Semiconductor: Contains an abundance of holes (positive charge carriers) due to the presence of acceptor impurities.
• N-Type Semiconductor: Contains extra electrons (negative charge carriers) from donor impurities.
• Creation of Junction: When p-type and n-type materials are joined, a depletion region forms at the junction where electrons and holes recombine.

Step 2: Learn How the Diode Functions

• Forward Bias Condition:
  • When the positive terminal of a voltage source is connected to the p-type side and the negative to the n-type side, the diode becomes forward-biased.
  • This reduces the width of the depletion region, allowing current to flow through the diode.
• Reverse Bias Condition:
  • When the connections are reversed, the diode becomes reverse-biased.
  • The depletion region widens, preventing current from flowing, except for a small leakage current.

Step 3: Explore the Current-Voltage Characteristics

• IV Curve: The current-voltage (IV) characteristics of the diode illustrate its behavior under different biasing conditions.
• Key Points on the IV Curve:
  • In forward bias, the current increases exponentially with voltage after a certain threshold (the forward voltage).
  • In reverse bias, the current remains nearly constant until breakdown occurs, which can damage the diode if excessive.

Step 4: Applications of PN Junction Diodes

• Rectifiers: Diodes convert alternating current (AC) to direct current (DC) in power supply circuits.
• Signal Modulation: Used in radio frequency applications for demodulating signals.
• Voltage Regulation: Zener diodes, a type of PN junction diode, are used for voltage stabilization.

Conclusion

Understanding the operation of a PN junction diode is crucial for grasping the principles of semiconductor devices. Key points include the formation of the depletion region, the effects of biasing, and the diode's current-voltage characteristics. As a next step, consider experimenting with diodes in simple electronic circuits to see their properties in action.